Lubricating composition



- Patented Mar. 3, 1942 UNITED STATES PATENT OFFICE- 2.214.673 wnmca'rmoCOMPOSITION Clarence E. Earle, Washington, D. C.

No Drawing. Application April 5, 1940,

Serial No. 328,095

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3700. G. 757) Claims.

manufactured and produced by compounding mineral oil and'metallic saltssuch as sodium stearate, potassium stear'ate, or the oleates or otherhigher fatty acid salts of these two metals or alkaline earth salts ofthese acids such as those of calcium, barium, strontium, etc. It issignificant to point out here that neither the literature nor the bookson the art mention the use of lithium salts of the higher fatty acids,such as stearates, oleates, palmitates, etc., for producing greases.

I have found that the use of lithium soap or salts of soap forminghigher fatty acids in the production of lubricating greases gives thegreases entirely different properties from those obtained by the use ofthe other alkali metal salts. The greases produced by my method arewater resistant, whereas the other alkali salts do not give such aproperty. My lithium soap greases withstand temperature greatly inexcess of those containing other alkali metal salts. The properties ofthese improved lubricating greases are not only widely different fromthe other alkali metal soap types but also they are much more stable totemperature and pressure, both chemically and physically.

I have found that the addition of polymerized esters of the acrylicseries materially improves the thixotropic properties of my lubricatingcompounds. Also I have found that the polymers of vinyl esters with longchains enhance the thixotropic properties of these improved lubricatingcompounds.

Various compositions of mineral oil or vegetable oil, lithium soaps anda stabilizing agent such as polymerized esters of the acrylic series canbe used in production of a lubricating grease. As an example, a mixturehaving the following formulation limits may be employed, the percentagesdepending upon the type of service for which it is intended:

Percent by weight Mineral nil 90-54 Lithium soap or salt 10-40Polymerized esters of methacrylic acid--- 0- 6 A preferred process ofpreparing the lubricating grease is as follows, for example: 85 parts ofa mineral oil is heated up to C. to 250 C. at'which temperature 14 partsof lithium stearate is added and the temperature maintained for twentyto thirty minutes. soap becomes thoroughly mixed with the oil, thetemperature is allowed to slowly recede. At about C. while the solutionis still fluid one part of cetyl methacrylate is added and thoroughlystirred-into the solution. The solution is allowed to cool and jellafter which it is ready for use. My invention includes the employment ofpolymerized esters of acrylic and methacrylic acids.

I have also found that the addition of small amounts of lithium soaps tolubricating oils improves their lubricating properties, thus loweringthe power consumption and leakage from bear ing interfaces.

The grease made in accordance with my infor governmental purposeswithout the payment of any royalties thereon or therefor.

I claim:

1. A lubricating composition comprising a mineral oil, and a lithiumsoap of a higher fatty acid in quantity sufiicient substantially tothicken said oil.

2. A lubricating composition comprising a vegetable oil and a lithiumsoap of a higher fatty acid in quantity sufllcient substantially tothicken said oil.-

' 3. A lubricating composition comprising a mineral oil, a lithium soapof a' higher fatty acid in quantity sufiicient substantially to thickensaid oil and a polymerized ester of acrylic acid.

4. A lubricating composition comprising a vegetable oil, a lithium soapof a higher fatty acid in quantity suflicient substantially to thickenand a polymerized ester of acrylic acid.

5. A lubricating composition comprising oleaginous material selectedfrom the group consisting of mineral oils and vegetable oils, a lithiumsoap of a higher fatty acid in quantity suflicient substantially tothicken and a polymerized ester of methacrylic acid.

6. A lubricating composition comprising oleaginous material selectedfrom the group consisting of mineral oils and vegetable oils, a lithiumsoap in quantity substantially to thicken, and a polymerized vinyl esterhaving a hydrocar- After the bon radical having an excess of 6 carbonatoms.

7. A lubricating-composition comprising oleaginous material selectedfrom the group con- 'sisting of mineral oils and vegetable oils, a Vlithium soap in quantity substantially to thicken,-

and a polymerized ester of acrylic acid.

8. As a new composition of matter, a lubricating grease comprising 54 to90 parts of an oleaginous material selected from the group consisting ofmineral and vegetable oils, 10 to 40 parts of a lithium soap of a higherfatty acid, and

not more than 6 parts of a polymerized lon'gchained ester of methacrylicacid.

1 ent in quantities suflicient substantially to thicken the oil.

CLARENCE E. EARLE.

